Package labels are usually printed separately and are added to a package later. Labels may printed on an adhesive substrate, for example, and adhered to a package after the package is printed. Labels may be printed by traditional or digital printing methods. Digital printing may provide variable label printing options. In certain cases, labels are printed directly on the package as well.
U.S. Patent Publication No. 2015/0101745 (Ramakrishnan et al.), entitled “Manufacturing of high resolution conductive patterns using organometallic ink and banded anilox rolls,” teaches printing an electronic grid for touch sensors. The process is achieved by flexographic printing, wherein two pre-patterned layers are prepared, each on a separate flexographic master and printed using those flexographic masters to form touch sensors. The process provides a very fine conductive pattern on a thin and flexible display. The process uses laser ablation on at least one axis of the grid lines by ablating a highly conductive film (HCF). Flexible displays are often based on organic light-emitting diode (OLED) which are still not in mass production and has numerous reliability, lifetime and yield issues. The electroluminescent flexible displays or touch sensors which are produced by printing methods, as the one described by Ramakrishnan et al., cannot provide as high resolution patterning results as laser ablation can achieve.
The usual packaging labels are printed using printing ink on various substrates such as paper and plastic. There remains a need for improved methods to print labels on packages with variable content.